The purpose of this project is to elucidate the molecular pathogenesis of squamous cell neoplasms of the upper aerodigestive tract, and to enable the development of approaches for molecular therapy for these disorders. Human and murine head and neck squamous cell carcinoma (HNSCC) cell line models have been developed and used to identify genes that are differentially expressed with tumor progression, using molecular and immune assays. Systems biology and bioinformatic analyses approaches are being used to identify gene programs and pathways involved in development of HNSCC. Proinflammatory cytokines, related signal transduction pathway molecules, and immediate early transcription factor genes have been shown to be overexpressed or activated with tumor progression, and are associated with aggressive growth and metastasis. [unreadable] [unreadable] Aim 1 Progress. We have obtained evidence that IKK1 (IKKalpha)and IKK 2 (IKKbeta) both contribute to activation of NF-kappaB, and identified a role for protein kinase CK2 in activation(Yu et al., Cancer Res., 2006; Van Waes, Clin Cancer Res. 2007). Studies are underway to determine if classical (IKK1/2 NF-kappaB1) and alternative (IKK1 NF-kappaB2) pathways are activated and contribute to gene expression and malignant phenotype of HNSCC, and may be inhibited by known and newly developed agents.[unreadable] [unreadable] Aim 2 Progress. NF-kappaB and p53 status have been implicated in expression of heterogeneous and common gene expression programs in HNSCC (Yan et al, Genome Biology, 2007). These signatures and pathway alterations have been associated with differences in prognosis. The expression and function of these candidate genes and pathways identified by microarray are being examined following overexpression or inhibition by transfection of tumors with dominant negative constructs or RNAi. The contribution of NF-kappaB to resistance to apoptosis and histone deacetylases, and effect of siRNA and proteasome inhibitor bortezomib to sensitize HNSCC was reported (Duan et al, Mol Cancer Therapeutics, 2007). [unreadable] [unreadable] Aim 3 Progress. In collaboration with the NCI Specialized Program of Research Excellence at University of Michigan, the potential of NF-kappaB regulated cytokines and growth factors to serve as proteomic markers of response, recurrence and survival was demonstrated in patients with oropharyngeal cancer following cisplatin and radiation therapy (Allen et al, Clin Cancer Res, 2007). An NIDCD/NCI trial of proteasome inhibitor bortezomib with reirradiation for patients with recurrent HNSCC is ongoing. A scheduled treatment break and IV fluid support was found to reduce hypotension obnserved in some patients, enabling dose escalation from 0.6 to 0.9 mg/m2. Five of seventeen patients treated at the initial dose level with different schedules have shown partial responses. A study combining bortezomib with Epidermal Growth Factor Receptor inhibitor cetuximab is under development.